Youtube adverts and some others

Ads seem to be blocked and forwarded

Expected Behaviour:

2017-07-31 11:54:47 IPv4 googleads.g.doubleclick.net 192.168.1.65 Pi-holed Whitelist

Actual Behaviour:

2017-07-31 11:54:47 IPv4 googleads.g.doubleclick.net 192.168.1.65 Pi-holed Whitelist
2017-07-31 11:54:47 IPv6 googleads.g.doubleclick.net 192.168.1.65 OK (forwarded) Blacklist

Debug Token:

wibds5zyd4

You don't have an IPv6 address set to block with. Run pihole -r to reconfigure.

I have noticed the same thing. Looking at the Windows DNS cache, it's evident that (when the internet dns server sends both A and AAAA records) dnsmasq returns AAAA records regardless of not choosing ipv6 in pi hole setup.
Look for "::" in the windows cache

ipconfig /displaydns
or
ipconfig /displaydns > cache.txt

I have never used ipv6, pihole has worked perfectly since I installed it last year and all I've done is kept it up to date. I don't have any ipv6 options enabled and they are all greyed out.